Art of 3D printer in the middle of printing a Hackaday Jolly Wrencher logo

3D Printering: Will A Resin Printer Retire Your Filament-based One?

April 30, 2020 by 25 Comments

Adding a resin printer to one’s workbench has never looked so attractive, nor been so affordable. Complex shapes with effortlessly great detail and surface finish? Yes, please! Well, photos make the results look effortless, anyway. Since filament-based printers using fused deposition modeling (FDM) get solid “could be better” ratings when it comes to surface finish and small detail resolution, will a trusty FDM printer end up retired if one buys a resin printer?

The short answer is this: for users who already use FDM, a resin-based stereolithography (SLA) printer is not likely to take over. What is more likely to happen is that the filament printer continues to do the same jobs it is good at, while the resin printer opens some wonderful new doors. This is partly because those great SLA prints will come at a cost that may not always justify the extra work.

Let’s go through what makes SLA good, what it needs in return, and how it does and doesn’t fit in with FDM.

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Using Valgrind To Track Down Known And Unknown Bugs In Your Code

April 29, 2020 by 17 Comments

We all know what bugs in code are. We don’t like them when they are in programs we use, and they’re even worse when they are in code which we have written. Clearly, the best code is bug-free, but how do we get there?

This isn’t a new question, of course, just one that has become ever more important as the total number of lines of code (LoC) that run modern day society keeps increasing and which is affecting even hobbyists more and more often now that everything has a microcontroller inside.

Although many of us know the smug satisfaction of watching a full row of green result markers light up across the board after running the unit tests for a project, the painful reality is that you don’t know whether the code really is functionally correct until it runs in an environment that is akin to the production environment.  Yet how can one test an application in this situation?

This is where tools like those contained in the Valgrind suite come into play, allowing us to profile, analyze and otherwise nitpick every single opcode and memory read or write. Let’s take a look, shall we?

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A DIY Functional F-35 Is No Simple Task

April 27, 2020 by 19 Comments

The advent of affordable gear for radio-controlled aircraft has made the hobby extremely accessible, but also made it possible to build some very complex flying machines on a budget, especially when combined with 3D printing. [Joel Vlashof] really likes VTOL fighter aircraft and is in the process of building a fully functional radio-controlled F-35B.

The F-35 series of aircraft is one of the most expensive defence project to date. The VTOL capable “B” variant is a complex machine, with total of 19 doors on the outside of the aircraft for weapons, landing gear and thrusters. The thruster on the tail can pivot 90° down for VTOL operations, using an interesting 3-bearing swivel mechanism.

[Joel] wants his model to be as close as possible to the real thing, and has integrated all these features into his build. Thrust is provided by two EDF motors, the pivoting nozzle is 3D printed and actuated by three set of small DC motors, and all 5 doors for VTOL are actuated by a single servo in the nose via a series of linkages. For tilt control, air from the main fan is channeled to the wing-tips and controlled by servo-actuated valves. A flight controller intended for use on a multi-rotor is used to help keep the plane stable while hovering. One iteration of this plane bit the dust during development, but [Joel] has done successful test flights for both hover and conventional horizontal flight.  The really tricky part will be transitioning between flight modes, and [Joel] hopes to achieve that in the near future.

The real Lockheed Martin F-35 Lightning II project is controversial because of repeated budget overruns and time delays, but the engineering challenges solved in the project are themselves fascinating. The logistics of keeping these complex machines in the air are daunting, and a while back we saw Marine ground crew 3D print components that they were having trouble procuring through normal channels.

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The Back And Forth Of Windshield Wipers And Patent Lawsuits

April 23, 2020 by 50 Comments

Who among us hasn’t dreamed of having some brainstorm idea, prototyping it, and then have some huge company put it into worldwide production? The problem is, that’s not really as easy as it sounds in most cases. Take the case of Robert Kearns. Never heard of him? You use the result of one of his patents pretty often; Kearns invented the intermittent windshield wiper.

If he had sold the patent to one of the big carmakers, this would be a short article. Not that he didn’t try. But it didn’t go very well and while, in the end, he prevailed, it was a very expensive victory.

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Limiting Factor Submersible Is In A League Of Its Own

April 22, 2020 by 26 Comments

Space may be the final frontier, but there are still Earthly frontiers that a select few have visited — the deepest depths of the high seas. Victor Vescovo, a Texas businessman and former Naval officer, is one of those few. Last spring, Vescovo realized his dream of becoming the first person to scrape the bottoms of all five oceans.

Vescovo descended alone in Limiting Factor, a $37 million two-seater submersible he commissioned from Triton, a private manufacturer who made this feat of engineering come to life. Vescovo and the crew discovered over 40 new species of aquatic lifeforms throughout the course of their Five Deeps expedition. But the attention-getting takeaway came when Vescovo visited the absolute lowest point on Earth. In the Challenger Deep portion of the Marianas Trench, seven miles below sea level, he saw a plastic bag drift by in the abyss.

One normal-sounding quirk sets this sub apart from others: it’s made to be reusable. You read that right, most super-deep divers never manage to dive over and over again.

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3D Printed Speakers With Many Lessons Learned

April 18, 2020 by 24 Comments

Although we all wish that our projects would turn out perfect with no hiccups, the lessons learned from a frustrating project can sometimes be more valuable than the project itself. [Thomas Sanladerer] found this to be the case while trying to build the five satellite speakers for a 5.1 surround sound system, and fortunately shared the entire process with us in all its messy glory.

[Thomas] wanted something a little more attractive than simple rectangular boxes, so he settled on a very nice curved design with few flat faces and no sharp corners, 3D printed in PLA. Inside each is an affordable broadband speaker driver and tweeter, with a crossover circuit to improve the sound quality and protect the drivers. The manufacturer of the drivers, Visatron, provides very nice speaker simulation software to select the appropriate drivers and design the crossover circuit. The front of each speaker consisted of a 3D printed frame, covered with material from a cut-up T-shirt. These covers attach to the main body using magnets and really look the part.

After printing, [Thomas] soaked all the parts in water to clean of the PVA support structures but discovered too late that the outer surfaces are not watertight and a lot of water had seeped into the parts. In an attempt to dry them he left them in the sun for a while which ended up warping some parts, so he had to reprint them anyway. The main bodies were printed in two parts and then glued together. This required a lot of sanding to smooth out the glue joints, and many cycles of paint and sanding to get rid of the layer lines. When assembling the different pieces, he found that many parts did not fit together, which he suspects was caused by incorrect calibration on the delta-bot printer he was using.

In the end, the build took almost two years, as [Thomas] needed breaks between all the frustration, and eventually only used one of the speakers. We’re glad he shared the messy parts of the project, which will hopefully spare someone else a bit of trouble in a project.

Listening to a high-quality audio setup is always a pleasure, and we’ve covered several projects from audiophiles, including affordable DML speakers, and 3D printed speaker drivers.

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Contest Winners: Machine Learning On All Kinds Of Gadgets

April 17, 2020 by 9 Comments

With nearly sixty exciting entries, the Train All the Things contest, presented in partnership with Digi-Key, has drawn to a close and today we are happy to share news of the winning projects. The challenge at hand was to show off a project using some type of Machine Learning and there were plenty of takes on this theme displayed.

Perhaps the most impressive project is the Intelligent Bat Detector by [Tegwyn☠Twmffat] which claims the “ML on the Edge” award. His project, seen above, seeks not only to detect the presence of bats through the sounds they make during echolocation, but to identify the type of bat as well. Having been through a number of iterations, the bat detector, based on Nvidia Jetson Nano and a Raspberry Pi, can classify several types of bats, and a set of house keys (for a “control”). It’s also been impeccably documented and serves as a great example of how to get into machine learning.

The Soldering LIghtsaber takes the “ML Blinky” award for using machine learning in the microcontroller realm. This clever use of the concept seeks one thing: destroying the wait times for your soldering iron to heat up. It takes time to make temperature readings while the iron heats up, if you can do away with this step it speeds things up greatly. By sampling results of different voltages and heating times, machine learning establishes its own guidelines for how to pour electricity into the heating element without checking for feedback, and coming out the other side at the perfect temperature.

AI Powered Bulls*** Detector
Wearables Fitness Trackers for Mental Health

Rounding up our final two winners, the AI Powered Bull**** Detector claims the “ML on the Gateway” award, and
Hacking Wearables for Mental Health and More which won in the “ML on the Cloud” category.

The idea behind our illuminated poop emoji project is to detect human speech and make a judgement on whether the comment is valid, or BS. It does this by leveraging a learning set of comments that have previously been identified as BS and making an association with the currently uttered words.

Wearables for mental health is a wonderful project that was previously recognized in the 2018 Hackaday Prize. Economies of scale have made these wearables quite affordable as a way to add a sensor suite to behavior analysis. But of course you need a way to process all of the sensor data, a perfect task for a cloud-based machine learning application.

All four winners received a $100 gift code to Tindie. Don’t forget to check out all of the other interesting projects that were entered in this contest!